Alternator Problems?

The alternator in my GMC Sierra was making a loud whistling whining type noise yesterday so I replaced it earlier today and I thought it was fixed but the new alternator has started to make the same noise. It seems kind of unusual that that 2 alternators could be bad in two days.Is there something else that could be causing this. Both alternators are Delco units and my truck is a 1995 with a 5.7 . Any help would be appreciatted, Thanks, Phil Wolf ps. the noise is not constant, and it seems to disappear when accellerating most of the time

Reply to
PW
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Is it the belt tensioner?

Reply to
News Group

Have the battery Checked , it may be developing a DEAD CELL The Whinning is Normal if the Alt is Charging a LOW battery or u draw lots of power out of the electrical system!

PW wrote:

Reply to
no one

Under a heavy load (high charging output) GM altenators can and will "whine" at idle and slightly above idle speeds, (sometimes quite noticably) this is not a defect. If it is a new noise for you then you should look for something in truck that is increasing load on altenator or a possible weak/bad battery too.

Reply to
SnoMan

Good point and another possibilty too.

Reply to
SnoMan

Are you certain the noise is from the Alternator? Use something for a Stethoscope to try to verify where the noise is coming from.

Reply to
Rich256

I can't speak for the original poster, but the last time I replaced a GM alternator, the first thing my SO asked was "Is it supposed to whine like that?"

So I yanked it off, took it back and got another one that had the same noise. Then I told her that it was a new feature so you would know it was working. Case Closed.

Greg

Reply to
Greg Surratt

Greg:

That is too funny!!! I am going to use that same line on my wife the next time she criticizes one of my repairs. SF

Reply to
sf/gf

The new alternator fixed the problem, I must of had a defective one. What are the odds of getting

2 bad alternators? Thanks to all that resp> I purchased an automotive stethoscope and the noise is definately
Reply to
PW

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